xref: /kernel/linux/linux-5.10/fs/erofs/inode.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2017-2018 HUAWEI, Inc.
4 *             https://www.huawei.com/
5 * Created by Gao Xiang <gaoxiang25@huawei.com>
6 */
7#include "xattr.h"
8
9#include <trace/events/erofs.h>
10
11/*
12 * if inode is successfully read, return its inode page (or sometimes
13 * the inode payload page if it's an extended inode) in order to fill
14 * inline data if possible.
15 */
16static struct page *erofs_read_inode(struct inode *inode,
17				     unsigned int *ofs)
18{
19	struct super_block *sb = inode->i_sb;
20	struct erofs_sb_info *sbi = EROFS_SB(sb);
21	struct erofs_inode *vi = EROFS_I(inode);
22	const erofs_off_t inode_loc = iloc(sbi, vi->nid);
23
24	erofs_blk_t blkaddr, nblks = 0;
25	struct page *page;
26	struct erofs_inode_compact *dic;
27	struct erofs_inode_extended *die, *copied = NULL;
28	unsigned int ifmt;
29	int err;
30
31	blkaddr = erofs_blknr(inode_loc);
32	*ofs = erofs_blkoff(inode_loc);
33
34	erofs_dbg("%s, reading inode nid %llu at %u of blkaddr %u",
35		  __func__, vi->nid, *ofs, blkaddr);
36
37	page = erofs_get_meta_page(sb, blkaddr);
38	if (IS_ERR(page)) {
39		erofs_err(sb, "failed to get inode (nid: %llu) page, err %ld",
40			  vi->nid, PTR_ERR(page));
41		return page;
42	}
43
44	dic = page_address(page) + *ofs;
45	ifmt = le16_to_cpu(dic->i_format);
46
47	if (ifmt & ~EROFS_I_ALL) {
48		erofs_err(inode->i_sb, "unsupported i_format %u of nid %llu",
49			  ifmt, vi->nid);
50		err = -EOPNOTSUPP;
51		goto err_out;
52	}
53
54	vi->datalayout = erofs_inode_datalayout(ifmt);
55	if (vi->datalayout >= EROFS_INODE_DATALAYOUT_MAX) {
56		erofs_err(inode->i_sb, "unsupported datalayout %u of nid %llu",
57			  vi->datalayout, vi->nid);
58		err = -EOPNOTSUPP;
59		goto err_out;
60	}
61
62	switch (erofs_inode_version(ifmt)) {
63	case EROFS_INODE_LAYOUT_EXTENDED:
64		vi->inode_isize = sizeof(struct erofs_inode_extended);
65		/* check if the inode acrosses page boundary */
66		if (*ofs + vi->inode_isize <= PAGE_SIZE) {
67			*ofs += vi->inode_isize;
68			die = (struct erofs_inode_extended *)dic;
69		} else {
70			const unsigned int gotten = PAGE_SIZE - *ofs;
71
72			copied = kmalloc(vi->inode_isize, GFP_NOFS);
73			if (!copied) {
74				err = -ENOMEM;
75				goto err_out;
76			}
77			memcpy(copied, dic, gotten);
78			unlock_page(page);
79			put_page(page);
80
81			page = erofs_get_meta_page(sb, blkaddr + 1);
82			if (IS_ERR(page)) {
83				erofs_err(sb, "failed to get inode payload page (nid: %llu), err %ld",
84					  vi->nid, PTR_ERR(page));
85				kfree(copied);
86				return page;
87			}
88			*ofs = vi->inode_isize - gotten;
89			memcpy((u8 *)copied + gotten, page_address(page), *ofs);
90			die = copied;
91		}
92		vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
93
94		inode->i_mode = le16_to_cpu(die->i_mode);
95		switch (inode->i_mode & S_IFMT) {
96		case S_IFREG:
97		case S_IFDIR:
98		case S_IFLNK:
99			vi->raw_blkaddr = le32_to_cpu(die->i_u.raw_blkaddr);
100			break;
101		case S_IFCHR:
102		case S_IFBLK:
103			inode->i_rdev =
104				new_decode_dev(le32_to_cpu(die->i_u.rdev));
105			break;
106		case S_IFIFO:
107		case S_IFSOCK:
108			inode->i_rdev = 0;
109			break;
110		default:
111			goto bogusimode;
112		}
113		i_uid_write(inode, le32_to_cpu(die->i_uid));
114		i_gid_write(inode, le32_to_cpu(die->i_gid));
115		set_nlink(inode, le32_to_cpu(die->i_nlink));
116
117		/* extended inode has its own timestamp */
118		inode->i_ctime.tv_sec = le64_to_cpu(die->i_ctime);
119		inode->i_ctime.tv_nsec = le32_to_cpu(die->i_ctime_nsec);
120
121		inode->i_size = le64_to_cpu(die->i_size);
122
123		/* total blocks for compressed files */
124		if (erofs_inode_is_data_compressed(vi->datalayout))
125			nblks = le32_to_cpu(die->i_u.compressed_blocks);
126
127		kfree(copied);
128		break;
129	case EROFS_INODE_LAYOUT_COMPACT:
130		vi->inode_isize = sizeof(struct erofs_inode_compact);
131		*ofs += vi->inode_isize;
132		vi->xattr_isize = erofs_xattr_ibody_size(dic->i_xattr_icount);
133
134		inode->i_mode = le16_to_cpu(dic->i_mode);
135		switch (inode->i_mode & S_IFMT) {
136		case S_IFREG:
137		case S_IFDIR:
138		case S_IFLNK:
139			vi->raw_blkaddr = le32_to_cpu(dic->i_u.raw_blkaddr);
140			break;
141		case S_IFCHR:
142		case S_IFBLK:
143			inode->i_rdev =
144				new_decode_dev(le32_to_cpu(dic->i_u.rdev));
145			break;
146		case S_IFIFO:
147		case S_IFSOCK:
148			inode->i_rdev = 0;
149			break;
150		default:
151			goto bogusimode;
152		}
153		i_uid_write(inode, le16_to_cpu(dic->i_uid));
154		i_gid_write(inode, le16_to_cpu(dic->i_gid));
155		set_nlink(inode, le16_to_cpu(dic->i_nlink));
156
157		/* use build time for compact inodes */
158		inode->i_ctime.tv_sec = sbi->build_time;
159		inode->i_ctime.tv_nsec = sbi->build_time_nsec;
160
161		inode->i_size = le32_to_cpu(dic->i_size);
162		if (erofs_inode_is_data_compressed(vi->datalayout))
163			nblks = le32_to_cpu(dic->i_u.compressed_blocks);
164		break;
165	default:
166		erofs_err(inode->i_sb,
167			  "unsupported on-disk inode version %u of nid %llu",
168			  erofs_inode_version(ifmt), vi->nid);
169		err = -EOPNOTSUPP;
170		goto err_out;
171	}
172
173	inode->i_mtime.tv_sec = inode->i_ctime.tv_sec;
174	inode->i_atime.tv_sec = inode->i_ctime.tv_sec;
175	inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec;
176	inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec;
177
178	if (!nblks)
179		/* measure inode.i_blocks as generic filesystems */
180		inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
181	else
182		inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
183	return page;
184
185bogusimode:
186	erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
187		  inode->i_mode, vi->nid);
188	err = -EFSCORRUPTED;
189err_out:
190	DBG_BUGON(1);
191	kfree(copied);
192	unlock_page(page);
193	put_page(page);
194	return ERR_PTR(err);
195}
196
197static int erofs_fill_symlink(struct inode *inode, void *data,
198			      unsigned int m_pofs)
199{
200	struct erofs_inode *vi = EROFS_I(inode);
201	char *lnk;
202
203	/* if it cannot be handled with fast symlink scheme */
204	if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
205	    inode->i_size >= PAGE_SIZE) {
206		inode->i_op = &erofs_symlink_iops;
207		return 0;
208	}
209
210	lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
211	if (!lnk)
212		return -ENOMEM;
213
214	m_pofs += vi->xattr_isize;
215	/* inline symlink data shouldn't cross page boundary as well */
216	if (m_pofs + inode->i_size > PAGE_SIZE) {
217		kfree(lnk);
218		erofs_err(inode->i_sb,
219			  "inline data cross block boundary @ nid %llu",
220			  vi->nid);
221		DBG_BUGON(1);
222		return -EFSCORRUPTED;
223	}
224
225	memcpy(lnk, data + m_pofs, inode->i_size);
226	lnk[inode->i_size] = '\0';
227
228	inode->i_link = lnk;
229	inode->i_op = &erofs_fast_symlink_iops;
230	return 0;
231}
232
233static int erofs_fill_inode(struct inode *inode, int isdir)
234{
235	struct erofs_inode *vi = EROFS_I(inode);
236	struct page *page;
237	unsigned int ofs;
238	int err = 0;
239
240	trace_erofs_fill_inode(inode, isdir);
241
242	/* read inode base data from disk */
243	page = erofs_read_inode(inode, &ofs);
244	if (IS_ERR(page))
245		return PTR_ERR(page);
246
247	/* setup the new inode */
248	switch (inode->i_mode & S_IFMT) {
249	case S_IFREG:
250		inode->i_op = &erofs_generic_iops;
251		inode->i_fop = &generic_ro_fops;
252		break;
253	case S_IFDIR:
254		inode->i_op = &erofs_dir_iops;
255		inode->i_fop = &erofs_dir_fops;
256		break;
257	case S_IFLNK:
258		err = erofs_fill_symlink(inode, page_address(page), ofs);
259		if (err)
260			goto out_unlock;
261		inode_nohighmem(inode);
262		break;
263	case S_IFCHR:
264	case S_IFBLK:
265	case S_IFIFO:
266	case S_IFSOCK:
267		inode->i_op = &erofs_generic_iops;
268		init_special_inode(inode, inode->i_mode, inode->i_rdev);
269		goto out_unlock;
270	default:
271		err = -EFSCORRUPTED;
272		goto out_unlock;
273	}
274
275	if (erofs_inode_is_data_compressed(vi->datalayout)) {
276		err = z_erofs_fill_inode(inode);
277		goto out_unlock;
278	}
279	inode->i_mapping->a_ops = &erofs_raw_access_aops;
280
281out_unlock:
282	unlock_page(page);
283	put_page(page);
284	return err;
285}
286
287/*
288 * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
289 * we should do more for 32-bit platform to find the right inode.
290 */
291static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
292{
293	const erofs_nid_t nid = *(erofs_nid_t *)opaque;
294
295	return EROFS_I(inode)->nid == nid;
296}
297
298static int erofs_iget_set_actor(struct inode *inode, void *opaque)
299{
300	const erofs_nid_t nid = *(erofs_nid_t *)opaque;
301
302	inode->i_ino = erofs_inode_hash(nid);
303	return 0;
304}
305
306static inline struct inode *erofs_iget_locked(struct super_block *sb,
307					      erofs_nid_t nid)
308{
309	const unsigned long hashval = erofs_inode_hash(nid);
310
311	return iget5_locked(sb, hashval, erofs_ilookup_test_actor,
312		erofs_iget_set_actor, &nid);
313}
314
315struct inode *erofs_iget(struct super_block *sb,
316			 erofs_nid_t nid,
317			 bool isdir)
318{
319	struct inode *inode = erofs_iget_locked(sb, nid);
320
321	if (!inode)
322		return ERR_PTR(-ENOMEM);
323
324	if (inode->i_state & I_NEW) {
325		int err;
326		struct erofs_inode *vi = EROFS_I(inode);
327
328		vi->nid = nid;
329
330		err = erofs_fill_inode(inode, isdir);
331		if (!err)
332			unlock_new_inode(inode);
333		else {
334			iget_failed(inode);
335			inode = ERR_PTR(err);
336		}
337	}
338	return inode;
339}
340
341int erofs_getattr(const struct path *path, struct kstat *stat,
342		  u32 request_mask, unsigned int query_flags)
343{
344	struct inode *const inode = d_inode(path->dentry);
345
346	if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))
347		stat->attributes |= STATX_ATTR_COMPRESSED;
348
349	stat->attributes |= STATX_ATTR_IMMUTABLE;
350	stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
351				  STATX_ATTR_IMMUTABLE);
352
353	generic_fillattr(inode, stat);
354	return 0;
355}
356
357const struct inode_operations erofs_generic_iops = {
358	.getattr = erofs_getattr,
359	.listxattr = erofs_listxattr,
360	.get_acl = erofs_get_acl,
361};
362
363const struct inode_operations erofs_symlink_iops = {
364	.get_link = page_get_link,
365	.getattr = erofs_getattr,
366	.listxattr = erofs_listxattr,
367	.get_acl = erofs_get_acl,
368};
369
370const struct inode_operations erofs_fast_symlink_iops = {
371	.get_link = simple_get_link,
372	.getattr = erofs_getattr,
373	.listxattr = erofs_listxattr,
374	.get_acl = erofs_get_acl,
375};
376
377